Решение
√(√23 - √19) * √(√23 + √19) + √(5√2 + 7) * √(5√2 - 7) =
= √(23 - 19) + √(50 - 49) = √4 + 1 = 2 + 1 = 3
1 5/6 + 0,5 × 10/3
1 5/6 + 5/3
11/6 + 5/3
21/6
А) (3m + n)(3m - n) = 9m² - n²
б) (x - 4y)(x + 4y) = x² - 16y²
в) (2x - m)² = 4x² - 4xm + m²
г) (2x)² - m² = 4x² - m²
Tg(a+b)=(tga+tgb)/1-tga*tgb)=(1/5+2/3)/(1-1/5*2/3)=1 ctg(a-b)= (1+3/2*5/2)/(3/2-5/2)=-4,75 tg(π/4+a)=(tgπ/4+tga)/(1-tgπ/4*tga)=(1+tga)/(1-tga) =(1+12/13*13/5)/(1-12/5) =17/7